Enhanced Antibacterial Activity of Nanocrystalline ZnO Due to Increased ROS-Mediated Cell Injury
Enhanced Antibacterial Activity of Nanocrystalline ZnO Due to Increased ROS-Mediated Cell Injury
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DOI：
10.1002/adfm.200801081
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发表时间：
2009-03-24
影响因子：
19
通讯作者：
Gedanken, Aharon
中科院分区：
文献类型：
--
作者：
Applerot, Guy;Lipovsky, Anat;Gedanken, Aharon
本文报道了一项旨在了解ZnO颗粒尺寸（从微米级到纳米级）对其抗菌效果的影响的创新研究。已经发现ZnO的抗菌活性是由于ZnO表面与水的反应。电子自旋共振测量表明，小纳米ZnO的水悬浮液产生的活性氧物种，即羟基自由基的水平增加。有趣的是，在抗菌处理后，检测到氧化应激的显著增强，超过了ZnO本身产生的水平。同样，细菌暴露于小ZnO纳米颗粒导致纳米颗粒的细胞内化增加和细菌细胞损伤。对两种细菌物种进行抗菌效果检查：大肠杆菌（革兰氏阴性）和金黄色葡萄球菌（革兰氏阳性）。采用超声辐照法制备了纳米ZnO粉体，并在超声处理过程中采用不同的溶剂控制了纳米ZnO粉体的粒径。作为一个整体来看，很明显，独特的性质（即，小尺寸和相应的大比表面积）的小纳米级ZnO颗粒施加了几种控制其抗菌作用的效果。这些效应是尺寸相关的，并且不存在于微米级颗粒范围内。
An innovative study aimed at understanding the influence of the particle size of ZnO (from the microscale down to the nanoscale) on its antibacterial effect is reported herein. The antibacterial activity of ZnO has been found to be due to a reaction of the ZnO surface with water. Electron-spin resonance measurements reveal that aqueous suspensions of small nanoparticles of ZnO produce increased levels of reactive oxygen species, namely hydroxyl radicals. interestingly, a remarkable enhancement of the oxidative stress, beyond the level yielded by the ZnO itself, is detected following the antibacterial treatment. Likewise, an exposure of bacteria to the small ZnO nanoparticles results in an increased cellular internalization of the nanoparticles and bacterial cell damage. An examination of the antibacterial effect is performed on two bacterial species: Escherichia coli (Gram negative) and Staphylococcus aureus (Gram positive). The nanocrystalline particles of ZnO are synthesized using ultrasonic irradiation, and the particle sizes are controlled using different solvents during the sonication pro cess. Taken as a whole, it is apparent that the unique properties (i.e., small size and corresponding large specific surface area) of small nanometer-scale ZnO particles impose several effects that govern its antibacterial action. These effects are size dependent and do not exist in the range of microscale particles.